Suit yourself
Definition 1 of 1
Pro Tip 1/3Slightly Dismissive
Can imply indifference towards another's choice or a mild form of irritation. 
You're not going to clean up? Well, suit yourself then.
Pro Tip 2/3Personal Decision
Emphasizes that the decision is entirely up to the person addressed, without external influence. 
Wear whatever you like to the event, suit yourself!
Pro Tip 3/3Casual Tone
Used in an informal setting, not suitable for formal or professional situations. 
If you don't want to watch the game with us, suit yourself.